AdGuardHome/internal/client/client.go

178 lines
4.0 KiB
Go

// Package client contains types and logic dealing with AdGuard Home's DNS
// clients.
//
// TODO(a.garipov): Expand.
package client
import (
"encoding"
"fmt"
"net/netip"
"github.com/AdguardTeam/AdGuardHome/internal/whois"
)
// Source represents the source from which the information about the client has
// been obtained.
type Source uint8
// Clients information sources. The order determines the priority.
const (
SourceWHOIS Source = iota + 1
SourceARP
SourceRDNS
SourceDHCP
SourceHostsFile
SourcePersistent
)
// type check
var _ fmt.Stringer = Source(0)
// String returns a human-readable name of cs.
func (cs Source) String() (s string) {
switch cs {
case SourceWHOIS:
return "WHOIS"
case SourceARP:
return "ARP"
case SourceRDNS:
return "rDNS"
case SourceDHCP:
return "DHCP"
case SourceHostsFile:
return "etc/hosts"
default:
return ""
}
}
// type check
var _ encoding.TextMarshaler = Source(0)
// MarshalText implements encoding.TextMarshaler for the Source.
func (cs Source) MarshalText() (text []byte, err error) {
return []byte(cs.String()), nil
}
// Runtime is a client information from different sources.
type Runtime struct {
// ip is an IP address of a client.
ip netip.Addr
// whois is the filtered WHOIS information of a client.
whois *whois.Info
// arp is the ARP information of a client. nil indicates that there is no
// information from the source. Empty non-nil slice indicates that the data
// from the source is present, but empty.
arp []string
// rdns is the RDNS information of a client. nil indicates that there is no
// information from the source. Empty non-nil slice indicates that the data
// from the source is present, but empty.
rdns []string
// dhcp is the DHCP information of a client. nil indicates that there is no
// information from the source. Empty non-nil slice indicates that the data
// from the source is present, but empty.
dhcp []string
// hostsFile is the information from the hosts file. nil indicates that
// there is no information from the source. Empty non-nil slice indicates
// that the data from the source is present, but empty.
hostsFile []string
}
// NewRuntime constructs a new runtime client. ip must be valid IP address.
//
// TODO(s.chzhen): Validate IP address.
func NewRuntime(ip netip.Addr) (r *Runtime) {
return &Runtime{
ip: ip,
}
}
// Info returns a client information from the highest-priority source.
func (r *Runtime) Info() (cs Source, host string) {
info := []string{}
switch {
case r.hostsFile != nil:
cs, info = SourceHostsFile, r.hostsFile
case r.dhcp != nil:
cs, info = SourceDHCP, r.dhcp
case r.rdns != nil:
cs, info = SourceRDNS, r.rdns
case r.arp != nil:
cs, info = SourceARP, r.arp
case r.whois != nil:
cs = SourceWHOIS
}
if len(info) == 0 {
return cs, ""
}
// TODO(s.chzhen): Return the full information.
return cs, info[0]
}
// SetInfo sets a host as a client information from the cs.
func (r *Runtime) SetInfo(cs Source, hosts []string) {
if len(hosts) == 1 && hosts[0] == "" {
hosts = []string{}
}
switch cs {
case SourceARP:
r.arp = hosts
case SourceRDNS:
r.rdns = hosts
case SourceDHCP:
r.dhcp = hosts
case SourceHostsFile:
r.hostsFile = hosts
}
}
// WHOIS returns a WHOIS client information.
func (r *Runtime) WHOIS() (info *whois.Info) {
return r.whois
}
// SetWHOIS sets a WHOIS client information. info must be non-nil.
func (r *Runtime) SetWHOIS(info *whois.Info) {
r.whois = info
}
// unset clears a cs information.
func (r *Runtime) unset(cs Source) {
switch cs {
case SourceWHOIS:
r.whois = nil
case SourceARP:
r.arp = nil
case SourceRDNS:
r.rdns = nil
case SourceDHCP:
r.dhcp = nil
case SourceHostsFile:
r.hostsFile = nil
}
}
// isEmpty returns true if there is no information from any source.
func (r *Runtime) isEmpty() (ok bool) {
return r.whois == nil &&
r.arp == nil &&
r.rdns == nil &&
r.dhcp == nil &&
r.hostsFile == nil
}
// Addr returns an IP address of the client.
func (r *Runtime) Addr() (ip netip.Addr) {
return r.ip
}